public class remove_duplicates_from_sorted_list {
    public ListNode deleteDuplicates(ListNode head) {
            if(head==null) return  head;
             ListNode cur=head;
             while(cur.next!=null){
                 if(cur.val==cur.next.val){
                     cur.next=cur.next.next;
                 }else {
                     cur=cur.next;
                 }
             }
             return head;
    }
}
